Frequently, day-to-day activities are organized around specific times. The ability to tell the time at any given point in a day has become an important aspect to the lives of many. Most often, one can determine the time visually by looking at a clock, such as on a watch or, more recently, a cellular device (cell phone, mobile phone). Alternatively, time can be communicated through audio. In rare instances, time is communicated through touch.
Telling time through touch has obvious benefits for those with seeing and/or hearing impairments. It may also be useful to convey the time discreetly. Those that are seeing impaired must detect time through other senses, and auditory clocks can be disturbing to those around. In addition, telling time through touch may prove useful to those who have traded in their wrist watches for the clock of a cell phone. In some situations, telling time with a cell phone may be difficult or dangerous (i.e., trying to wrestle a phone out of a front pocket while driving), or disturbing to other people (i.e., turning on the back light of the phone while in a dark theater).
Vibration has been used to report the time. However, using vibration has thus far involved pulsing out the hour and pulsing out the minutes in complicated sets of vibrations. Past methods have been long, unwieldy, hard to remember, and/or difficult to interpret. Additionally, these methods attempt a degree of precision unnecessary for many people's needs.